Attention is directed to the above identified application. In order to manufacture the step stool disclosed in that application in the form of molded plastic parts or similar material, which in general practice cannot exceed 3/16 inch in thickness at any one area, certain differences in construction have been made in order to provide for a sturdy structure which however is operable just as easily as that disclosed in said application; that is, the operator merely grasps handles at the ends of the top portion of the device and gives it a relatively mild shake, whereupon the legs snap out as by gravity and the strut is biassed into leg supporting and clamped position with respect thereto.